Heater control



June 20,1944. (3. A. DE GIERS ETAL 2,351,668

HEATER CONTROL Filed March 31, 1942 Patented June 20, 1944 HEATER CONTROL Clarence A. 'de Giers, Forest Hills, and Arthur Wickesser, St. Albans, N. Y., assignors to The Liquido'meter 'Corporation, Long Island City, N. Y., a corporation of Delaware ApplicationMarch 31, 1942, SerialNo. 437,000

'7 Claims.

I This invention pertains to means for regulating the fire in a heater forming part of apparatus for control of temperature in a space such as a refrigerator car.

In such service it is necessary at times to supply heat and at other times to remove heat. The removal of heat is usually brought about by ice carried in the car. The supply of heat is accomplished in the present case, by a burner using fuel such as coal or charcoal and an object of the invention is to disclose apparatus for controlling the fire in order to have suitable heat available whenever needed.

Another object is to regulate the fire under control of a thermometric device in a heating medium arranged to circulate through the space to be heated.

Another object is to regulate the heat by means of a damper under control of a thermometric device in the circulating medium.

Further and other objects and advantages will be apparent from the specification and claims, and from the accompanying drawing which illustrates what is now considered to be a preferred embodiment of the invention.

In the drawing, 2 is a firebox having a grate 4 for supporting fuel 6, preferably charcoal. Rising from the firebox is a stack 8 having a damper Ill pivoted at I2 and rotatable by arm l4 fulcrumed at l6, through the instrumentality of link I8 and arm 28 fast on pivot pin l 2. Above the fire is a coil 22 forming part of a closed liquidcirculating system, from which heated liquid, preferably an anti-freeze solution, flows through pipes 24, 26 to the space to be heated, returning therefrom through pipe 28. Whether or not liquid circulation takes place through circuit 24, 26 and coil 22 is determined by thermometric devices placed in the space to be heated. One of said thermometric devices I 60 placed in the space to be heated is indicated diagrammatically and is connected to suitable bellows within the casing I38 which control the flow of liquid in the circulating system 24, 26, 28. The elements I68 and I38 correspond respectively to the elements 68 and 38 presently to be described. A function of the present invention is to see that coil 22 is maintained within proper temperature limits so as to be able to supply the necessary heat when, and if, called for by the space thermometer.

Within firebox 2 is a second coil 30, its lower end connected by pipe 32 to the bottom of an external cooling circuit which may have a coil 34, the top oi. which is connected by pipe 36 to the interior of instrument case 38. The 'top of coil 30 is connected by pipe 48 to the interior of bellows 42, and has a branch pipe 44 leading to a chamber 46, sealed from, or opened to, the in terior of casing 38, depending on whether or not valve 48 is open or shut. Within casing 38 are liquid-filled bellows 50, 52 interconnected by floating link 54, and connected by tubes 56, 58 to thermometer bulb 68 within pipe 24, all, in well known manner as described, for instance, in Patent No. 1,942,267, issued January 9, 1934 to C. A. de Giers, one of the present inventors.

Link 54 is connected at its mid-point by pin 62 to lever 64 fulcrumed at 66. The free end of lever 64 is operably connected by stem 68 to valve 48. A compression spring 70 tends to depress lever 64.

With valve 48 open, as shown, the fluid in coil 38 circulates by convection through pipe 40, pipe 44, valve 48, casing 38, pipe 36, cooling coil 34, returning through pipe 32 to coil 30. Under such conditions there is little or no pressure in bellows 42 and damper I 0 remains closed. At the same time the space-heating liquid is circulating from coil 22 in the firebox through pipes 24, 26 to the space to be heated, from which it returns to coil 22 through pipe 28.

When the liquid in the heating system just described has cooled to a predetermined temperature, contraction of the liquid in thermometer bulb causes bellows 50, 52 to actuate lever 64 and close valve 48, stopping circulation from coil 38 to cooling coil 34, thus causing the temperature of coil 30 to rise until expansion of the fluid contents thereof will elongate bellows 42, raising lever I 4 and rotating damper l0 toward its dotted line position. The draft thus created increases combustion and raises the temperature of the space-heating liquid in coil 22 and pipe 24. When that temperature has increased to a predetermined point bulb 60 will cause valve 48 to reopen and circulation from coil 38 through coil 34 will be resumed, coil 34 will cool, damper l0 will close and remain so until the thermometer again causes valve 48 to close, completing the cycle, thus maintaining the heater temperature within the limits prescribed by thermometer 60.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by the following claims.

We claim:

1. In a control device for a heater, a fluid circulating system comprising a pipe coil in said heater, piping leading from the top of said coil into a comparatively cool space without said heater and thence back to the bottom of said coil, whereby said fluid normally circulates through said system, in combination with thermally-controlled means for obstructing said circulation, thereby, causing expansion of the fluid in said coil, said expanded fluid being eiiective to operate said heater control device.

2. The invention set forth in claim 1 in which a bellows is connected to said system above said coil and in which said bellows is elongated by said expanded fluid and jthereby operates said heater control device.

3. The invention set forth in claim l -in which said heater is provided with a stack, and a damper in said stack, and in which said expanded fluid is efiective for operating said damper.

4. The invention set forth in claim 1 in which 'a liquid circulating heating system passes through said heater into a space to be heated} and in which said obstructing means comprises a valve under control of a thermometric device in said heating system. 1

5. The invention set 'fo'rthi'n claim 1 in which a liquid circulating heating system passes through said heater into a space to be heated,

and in which said obstructing means comprises a valve operable by bellows under control of a thermometric device in said heating system.

6. The combination with a closed liquid-circulating system having a heater for heating the liquid therein and having its flow of liquid thermometrically controlled in accordance with the temperature of a space to be heated, of a thermally-responsive device exposed to the liquid in the input side of said system, a control device for the heater, and pressure-responsive means energized by the heater and controlled by said last mentioned thermally-responsive device for actuating said control device.

'7. The combination with a closed liquid-circulating system having a heater for heating the liquid therein and having its flow of liquid thermometrically controlled in accordance with the temperature of a space to be heated, of a theranally-responsive device exposed to the liquid in 

